I just started loading .308 win. I loaded some 100 grain Speer plinkers and some 110 grain Hornady V-Max bullets. The OAL listed for them was the same, but the V-Max is a much longer bullet. Anyhow, how do you measure OAL? I assumed from the base of the cartridge to the tip of the bullet. Am I wrong? This doesn't seem to be the proper way to do it though, because the contact point with the rifling varies with each type of bullet. Also, my LEE rifle die would not adjust far enough down to set these bullets within 100 thousandths of the minumum OAL, why not? Also, I have read that it is good to seat the bullet about 15 thousandths away from the rifling, then I read it should just barely touch the rifling. Which is correct? Also, How do you tell where the rifling is on your rifle so that you know what length you want?

Sorry for all the questions in a row, but I'm pretty new to rifle loading and I know you guys have the answers.

KilgoreII. So many questions, so little time. Oh well. First OAL. That is just the Over All Length, IE OAL. The bullets you were using, are too short to seat to within 15 thousanths, so just seat the out as far as you can, and still hold the bullet in the case while feeding from the magazine. That's what I do. Try about one eight inch into the case as a starter.
Seating close to the rifling is another matter. It depends on the individual rifle, and is something you really have to experiment with.
I'm not too sure I can explain how I do it, but I'll try.
Take a resized case, no powder or primer, and seat the bullet out so you know it is too long. You can smoke the bullet or color it with a Magic Marker over the whole bullet so it is blackened. Holding the rifle, muzzle down, carefully insert the dummy round into the chamber, and apply just enough pressure with the bolt to contact the rifling. If you go too far, the bullet will stick in the rifling and you'll have to start over again. Remove the dummy round, and reseat the bullet a bit deeper by turning the seating stem on the die by one turn. Repeat the chambering and bullet seating process until there are no rifling marks on the bullet. When you get close to that point, it is advisable to only turn the seating stem by half or quarter turns. At the point where there are no more marks, turn the seating stem in about one half to one full turn, and lock it down. This should give you a reasonable starting point, and for me at least, has given good accuracy in most of my rifles.
I hope this clears it up for you.
Paul B.

OAL in a repeating rifle may be limited by the maximum length of the magazine well. Max OAL for a chamber will depend on the shape of the bullet (ogive), how soon the rifling starts and how abruptly it begins.

Neck size a case so it's just barely tight enough to hold a bullet. You should be able to push the bullet into the case with finger pressure alone. Seat the bullet really long, so you know it will touch the rifling. Then, carefully chamber the (dummy) round and close the bolt. This will push the bullet into the case. Extract it and measure its length. Repeat this several times, until you're satisfied that the reault is consistent. The OAL you get is for the bullet in contact with the rifling. Simply subtract from that, the distance you want the bullet to be from the rifling. That's your working OAL for that bullet.

Here is another method to get your measurement of where the lands of the rifleing start.

If you remove the bolt, and making sure that the gun is unloaded, Drop which ever bullet, not loaded round, you are thinking of shooting down the tube nose first. It will stop when it gets to the lands. At this point apply a small amount of pressure to the base of it with a wood dowel or pencil. Now slowly slide a cleaning rod in from the muzzle. You will feel it hit the tip of the bullet. With a marker, make a mark about 3/8" wide in the area just inside the muzzle and continue to just outside the muzzle. This will allow you to scibe a light line in the dried ink. Once this is done then pop the bullet out of the chamber and reinsert the bolt. Repeat the above proceedure and make and scribe another mark. Now with dial calipers you can measure the distance between the marks and get a good OAL to the lands of your rifle. It might not be within .001" but it will be close enough to know where you stand with the loaded round.

I know this sounds like a lot of trouble, but it only takes a minute or two to complete and can be done with items already on hand.

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